Many techniques and devices are available to separate and analyze biomolecules, particularly those biomolecules found in the human body. Present day medical care and treatment focuses on the diagnosis of disease, disfunctions and abnormalities based on the laboratory analysis of bodily fluids, such as blood, using the tools of modern science. Biomolecule sample work-up prior to profiling often requires preservation and the separation into components. Evaluation may be of the various individual components, or groups of components.
Medical testing of a wide variety of different body fluid components is desirable based on developed testing and diagnostic protocols. Such testing and analysis is used to indicate and evaluate various diseases, or other medical conditions. Having the ability to separate and preserve the biomolecules into components for sampling reliably, cost effectively and without contamination enhances the ability to discover and develop new knowledge about diseases, treatments and cures.
Methods for medical and scientific evaluation of components significantly depend on the ability to adequately separate and preserve the components intact, providing pure and uncompromised samples for evaluation based on comparison of healthy and diseased biomolecules. Many techniques and devices are available to make these analyses. The particular ones used will vary with the biomolecule components of concern. These procedures typically require considerable care and attention. The ability to easily collect, separate and analyze biomolecules without risk of contamination is important.
To acquire biomolecules for sampling and analysis is not trivial. For example, the storage of highly labile biomolecules, such as proteins and RNA, requires the use of low (4° C. and −20° C.) and ultra-low (−80° C.) freezers and/or a host of specialized and expensive chemicals to preserve the structural and chemical integrity of the biomolecule. Because of these storage requirements, storing millions of samples to use for early diagnosis is cost prohibitive and impractical. Presently, alternatives to low and ultra-low temperature storage have significant drawbacks.
Evaluation of blood and its components is a particular focus for diagnosis and treatment of many different medical conditions. Human blood comprises a plasma component, and a blood corpuscle component. The blood corpuscle component comprises erythrocytes (i.e., red blood cells), leucocytes (i.e., white blood cells), and blood platelets. The blood plasma component comprises water (90% by volume), dissolved proteins, nucleic acids, glucose, clotting factors, mineral ions, hormones and gases (e.g., carbon dioxide).
Information derived from the analysis of proteins and nucleic acids derived from blood and other fluids and tissues has provided early detection of and diagnosis capability for many medical conditions. For example, analysis of blood proteins and nucleic acids can detect illnesses such as post-traumatic stress disorder (PTSD), traumatic brain injury (TBI) as well as other “hidden” illnesses. The ability to provide early detection and diagnosis facilitates the successful evaluation and treatment of these and other illnesses.
To avoid the stringent demands for low and ultra-low temperature storage required preserve structural and chemical integrity for blood and other fluids, there are preservation methodologies such as those for ribonucleic acid (RNA)/deoxyribonucleic acid (DNA) storage that provide for stabilizing the RNA during collection, processing and storage; however, these technologies are subjectively dependent on the selective ability to extract and purify RNA with minimal exposure to contaminating ribonucleases (RNases). Because RNases are ubiquitous in the clinic and laboratory, clinicians are unable to institutionalize reliable procedures for avoiding contamination.
In an attempt to overcome the inherent problems with RNases contamination, several commercially reagents, such as RNAlater® (Ambion, Austin, Tex.), have been developed to avoid RNases degradation during sample collection, processing and storage. To avoid contamination, these reagents provide for the in situ precipitation of degenerative RNases in cells/living tissues via use of ammonium sulfate. While these reagents theoretically provide for the storage of RNA samples at near room temperature for up to seven (7) days, actual use shows that there is significant mRNA degradation that may occur after three (3) days of near-room temperature storage.
More recently, a new RNA storage reagent trading under the name of RNAstable® (Biomatrica, San Diego, Calif.) was introduced using anhydrobiosis as a method to stabilize and protect biomolecules from degradation at near room temperature. RNAstable® has been shown to store total RNA at near room temperature, and is claimed to do so for up to twelve (12) years according to manufacturer's specifications.
While RNAstable® and other reagents may ultimately provide for longer RNA storage, the use of a reagent generally is highly dependent on the ability to collect, process and, if necessary, purify samples while minimizing any incidence of RNases contamination.
With regard to protein storage, there is currently no commercially available means of storage other than the low and ultra-low temperature methodology. Alternative methodologies exist but are deficient. For example, for blood analysis, alternatives include drying out the sample and adhering it to dried blood spot (DBS) papers or cards (Shleicher & Scheull 903). Current DBS technology is limited and an inferior substitute for low and ultra-low temperature storage of samples. Special training of personnel handling the placement of the blood on the papers/cards is required or large variations and errors can result. For example, DBS papers in use are subject to operator inefficiencies and lack of skill. Operator errors in the distribution of the samples on the matrix is often non-uniform, leading to assay variations (upon recovery). And, samples are recovered using a punch device, which can lead to cross-contamination among samples.
Accordingly, there is a need for an improved method and apparatus for preserving and storing biomolecules. There is an additional need for an improved method and apparatus for long-term storage of biomolecules. There is also a need for an improved method and apparatus for storage of biomolecules at ambient conditions. There is a further need for a method and apparatus that reduces the possibility of sample cross-contamination. There is an additional need for a practical and cost-effective method and apparatus for processing biological samples at the point of sample collection (or point of care) without the need for a laboratory or complicated laboratory processing.